Skanska’s underground construction specialist Cementation Skanska has negotiated exclusive rights to use a new, pioneering 3D technology in the EU and beyond that can see through the ground.
The service is known as 3D Tomographics (3dT) and has been developed in the USA. It produces 3D computer images of inside the ground, showing density contrasts and identifying geological structures, cavities and man made excavations.
The technology reduces underground engineering construction risk quickly and economically by minimising uncertainties and alerting projects early to costly adverse conditions, allowing sufficient time for remedial plans.
3dT uses sophisticated computer software to process raw seismic (sound) signals and convert into 3D images (like a medical CAT scan). The signals are generated both at the surface and inside boreholes drilled into the ground.
Prior to using 3dT, the raw data gained from traditional geophysical methods of seismic reflection and refraction would be shown on graphs. 3dT enables this information to be viewed in three-dimensional holographic format on a computer.
The applications in underground engineering include locating features and defining rockhead profiles. 3dT has also been adapted specifically for use in tunnels and in mines, where images can be produced looking up to 150 metres ahead of a face.
Cementation Skanska is applying 3dT on a project to survey the historic Silbury Hill, a Neolithic monument in Wiltshire, for English Heritage.
It will map the hill’s interior following the appearance of a hole on the summit thought to have been caused by the collapse of 18th and 19th century exploratory shafts. The 3D computer images of inside the Hill will help identify the extent of the weaknesses that are causing the hole.
The results will allow English Heritage to develop a programme of repairs and forms an essential part of its plan to ensure the long-term stability of Silbury Hill.
Cementation Skanska was appointed in July after a competitive tendering process and preliminary work is due to start at the end of this month with completion by winter.